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3 years ago

Which two practices are examples of how people use science?

Chemistry

2 answers:

BigorU [14]3 years ago

8 0

Answer:

Explanation:

Anika [276]3 years ago

4 0

B. Developing theories using many lines of evidence

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The natural distribution of the isotopes of a hypothetical element is 60.795% at a mass of 281.99481 u, 22.122% at a mass of 283

fenix001 [56]

Answer: The average atomic mass of the element is 283.291 amu

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

For isotope 1:

Mass of isotope 1 = 281.99481 amu

Percentage abundance of isotope 1 = 60.795 %

Fractional abundance of isotope 1 = 0.60795

For isotope 2:

Mass of isotope 2 = 283.99570 amu

Percentage abundance of isotope 2 = 22.122 %

Fractional abundance of isotope 2 = 0.22122

For isotope 3:

Mass of isotope 3 = 286.99423 amu

Percentage abundance of isotope 3 = [100 - (60.795 + 22.122)] = 17.083 %

Fractional abundance of isotope 1 = 0.17083

Putting values in equation 1, we get:

$\text{Average atomic mass of element}=[(281.99481\times 0.60795)+(283.99570\times 0.22122)+(286.99423\times 0.17083)]\\\\\text{Average atomic mass of element}=283.291amu$

Hence, the average atomic mass of the element is 283.291 amu

5 0

4 years ago

Hydrogen peroxide solution for hair bleaching is usually prepared by mixing 5.0g of hydrogen peroxide H2O2 per 100 ml of solutio

madam [21]

molarity = moles solvent/L solute

gram formula mass of H2O2: 34g/mol

5g/34g = 0.14705882352

100ml * 10^-3 = 0.1L

0.14705882352moles/0.1L = 1.47M

7 0

4 years ago

What is the mass of solute dissolved in 50,0 g of 12.5% saline solution? A) 7.148 B) 6.258 C) 43.88 D) 4.00 g

Marizza181 [45]

Answer:

6.25 grams is the mass of solute dissolved.

Explanation:

w/w % : The percentage mass or fraction of mass of the of solute present in total mass of the solution.

$w/w\%=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 100$

Mass of the solution = 50.0 g

Mass of the solvent = x

w/w % = 12.5%

$12.5\%=\frac{x}{50.0 g}\times 100$

x = 6.25 g

6.25 grams is the mass of solute dissolved.

6 0

3 years ago

9. The pH of an acidic solution is

tresset_1 [31]

Answer: d

Explanation:

7 0

3 years ago

The dehydration of the alcohol functional group is a widely used reaction in organic chemistry. The mechanism is generally accep

puteri [66]

Answer:

Elimination
Elimination
Zaitsev
Zaitsev
Carbocation

Explanation:

The mechanism is generally accepted to always operate via an ELIMINATION step-wise process.

The ELIMINATION mechanism process will always produce (after dehydration) a ZAITSEV style alkene as major product

The driving force for the production of this ZAITSEV style alkene product is generally going to be determined by stability of the CARBOCATION

Elimination mechanism is the removal of two substituents from a molecule in either a one- or two-step mechanism

Carbocation is a molecule containing a positive charged carbon atom and three bonds

3 0

3 years ago